Bug 54110693: [React Native Gallery -> Home]: 'Scroll right' or 'Scroll left' button is not visible clearly in high contrast theme.

[Yajur-Grover]

Build Details:
OS Version: Dev (OS Build 27695.1000)
App: React Native Gallery
App Version: 1.0.18.0
React Native Windows Version: 0.75.0
AT: High Contrast

Pre-Requisite:
Turn on High Contrast Aquatic Theme (Settings->Accessibility->Contrast themes->Aquatic/Dessert theme->Apply)

Repro-Steps:
Launch the React Native Gallery app.
Navigate to ‘Home’ button present in left navigation pane and invoke it.
Now observe 'Scroll right' or 'Scroll left' button in high contrast themes.
Actual Result:
'Scroll right' or 'Scroll left' button is not visible clearly in high contrast theme.

Expected Result:
'Scroll right' or 'Scroll left' button should be visible clearly in high contrast theme.

User impact:

Users with low vision will not be able to identify the presence of the buttons if it is not visible in High Contrast Themes.

Link to ADO bug: https://microsoft.visualstudio.com/OS/_workitems/edit/54110693